1. Field of the Invention
The present invention relates to the field of portable radiotelephones, and more particularly, for inputting data into such devices.
2. Description of the Prior Art
Current portable radiotelephones provide a host of features in addition to that of making and receiving telephone calls. Such additional features include the storing and retrieving of telephone numbers and names from an internal phone book, to the sending of textual messages to other users.
Current portable radiotelephones generally comprise at a least a numeric keypad, for composing telephone numbers, and a number of additional function keys, for initiating communications to a desired telephone number, turning the radiotelephone on and off etc. It is also common for the numeric keypad to also contain alphabetic representations, for allowing the construction of textual messages. Typically, each numeric key represents three alphabetic characters, for example, the numeric key xe2x80x982xe2x80x99 often also represents characters xe2x80x98Axe2x80x99, xe2x80x98Bxe2x80x99 and xe2x80x98Cxe2x80x99. During the construction of a textual message, each press of a numeric key causes a display to cycle through each character represented by that key. For example, a first press of numeric key xe2x80x982xe2x80x99 would cause the character xe2x80x98Axe2x80x99 to be displayed, a second press would cause the character xe2x80x98Bxe2x80x99 to be displayed and so on. When the desired character is displayed, a further character may be entered either after a short delay, or by pressing another key. In this way textual messages may be constructed. A textual message may then be transmitted to another user in a variety of ways which will be apparent to those skilled in the art.
One problem with the above method is that the construction of textual messages is somewhat arduous since each key may require multiple presses in order to select the required character.
In order to overcome this problem, some radiotelephones now comprise typewriter style keyboards. Whilst allowing the easier entry of text, such keyboards are large and cumbersome. Radiotelephones incorporating such keyboards are thus also large. Reducing the size of such a keyboard, however, makes it increasingly difficult to select the required key, since the keys of the keyboard become smaller than the size of a finger tip, and results in an increased chance of the wrong key being pressed.
Accordingly, one aim of the present invention is to provide improved data input means for use with a portable radiotelephone.
According to a first aspect of the present invention, there is provided apparatus for selecting a character from a predetermined set of characters comprising: means for presenting to a user a first plurality of selectable choices, at least one of which represents a sub-set of said set of characters; input means for selecting one of said first plurality of selectable choices; means for presenting to a user a second plurality of selectable choices, at least one of which represents a character of said selected sub-set; and means for selecting a character.
According to a second aspect of the present invention, there is provided a method of selecting a character from a predetermined set of characters comprising: presenting to a user a first plurality of selectable choices, at least one of which represents a sub-set of said set of characters; selecting one of said first plurality of selectable choices; presenting to a user a second plurality of selectable choices, at least one of which represents a character of said selected choice; and selecting a character from said second plurality of selectable choices.
This has the advantage of allowing easy entry of alphanumeric data into a portable radiotelephone without requiring a large keyboard. Additionally, the requirement for multiple presses of numeric keys associated with alphabetic characters is also removed. The present invention is particularly advantageous for portable radiotelephones or similar devices which do not have a keyboard due to their small size. In addition, the present invention provides a quick, accurate and efficient way of entering data in a single-handed operation.
The present invention also has advantages over pen-entry systems, such as character recognition systems, wherein a pen-like element is wiped over a touch sensitive pad and a controller attempts to interpret the movements made in order to recognize the character being written. These systems are inherently slow and difficult to use and require the user to make precise movements to ensure the correct character is recognized. Failure to make precise movements often leads to the recognition of an erroneous character. In such systems, the pen-like element is easily lost, rendering data input extremely difficult.
Advantageously, the number of selectable choices presented to the user is limited to the number of defined positions of the input device. By the limiting the number of selectable choices in this way, and by arranging the presentation of the selectable choices according to the positions of the input device allows any selectable choice to be made with only one user input.
The present invention may also be implemented to allow full or partial control of a portable radiotelephone, thereby eliminating the need for a data input keypad.